Core C is responsible for the biochemical analysis of markers of oxidative stress in plasma and tissue samples generated from the experimental animal and human studies. Determinations of plasma samples will include Plasma Renin Activity (PRA) and content (PRC), Angiotensin II (ANG II), Isoprostane (free), Total Antioxidant Capacity, Creatinine, and sodium/ potassium. In addition, tissue analysis of Angiotensin II, Nitrotyrosine, NADPH oxidase (p47), Isoprostane (total) and dihydroethidium (DHE) will be performed. This data will give important information about the relationship between renal humoral factors, oxidative stress, and renovascular hypertension.